 
a {
  color: inherit;
}

.m-modal__interior {  
  text-align: center;
  padding-top: 20rem;

}

.btn {
  background-color: green;
  padding: 1em 3em;
  border-radius: 3px;
  text-decoration: none;
}

.m-modal__window {
  position: fixed;  
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  opacity: 0;
  pointer-events: none;  
  transition: all 0.3s;
}

.m-modal__window:target {
  opacity: 1;
  pointer-events: auto;
}

.m-modal__window>div {
  width: 400px;
  position: relative;
  margin: 10% auto;
  padding: 2rem;
  border: 1px solid red; 
} 

.m-modal__close {
  color: #fff;
  background-color: red; 
  font-size: 80%;
  position: absolute;
  right: 1rem;
  text-align: center;
  top: 1rem;
  width: 70px;
  text-decoration: none;
}

 
 
 